/*
 * Title:        CloudSim Toolkit
 * Descripimport java.util.Random;
mulation) Toolkit for Modeling and Simulation of Clouds
 * Licence:      GPL - http://www.gnu.org/copyleft/gpl.html
 *
 * Copyright (c) 2009-2012, The University of Melbourne, Australia
 */

package cloudsim.distributions;

import org.apache.commons.math3.distribution.ParetoDistribution;

import java.util.Random;

/**
 * A pseudo random number generator following the
 * <a href="https://en.wikipedia.org/wiki/Pareto_distribution">Pareto</a> distribution.
 *
 * @author Marcos Dias de Assuncao
 * @since CloudSim Toolkit 1.0
 */
public class ParetoDistr implements ContinuousDistribution {

    /**
     * The internal Pareto pseudo random number generator.
     */
    private final ParetoDistribution numGen;

    /**
     * Instantiates a new Pareto pseudo random number generator.
     *
     * @param seed     the seed
     * @param shape    the shape
     * @param location the location
     */
    public ParetoDistr(Random seed, double shape, double location) {
        this(shape, location);
        numGen.reseedRandomGenerator(seed.nextLong());
    }

    /**
     * Instantiates a new Pareto pseudo random number generator.
     *
     * @param shape    the shape
     * @param location the location
     */
    public ParetoDistr(double shape, double location) {
        numGen = new ParetoDistribution(location, shape);
    }

    @Override
    public double sample() {
        return numGen.sample();
    }

}
